Heating composition.



PATENTED JAN. 17, 1905.

E. KAFKA. HEATING COMPOSITION.

APPLIOATION FILED OUT. 3. 190 1.

IIVI/E/l/TOR Ema? jfaf/a ATTORNEYS ployed in largeenough quantities.Mixing it x ar 780,352.

. I UNITED STATES EM'IL KAFKA",

- Patented 17, 1965.

OF'-NEW YORK, N. n, assienoa r FIRELESS HEATING GGMPANY, on NEW YORK, N.Y., a ,FIRM.

H EATING COM POSITION sracrmca'nou fominflart of Letters Patent No.780,852, am January 17, 1908.

. the following is a'full, clear, and exact deerin,&c.produces no Now 1have discovered that by the use of a -bodies is very being melted theywill upon cooling to thelr temperature ofi fusion remain at thattempound.

scription. L

My invention relates to the retention of heat and emitting it for longperiods.

It is well known that certain chemicals have the property of aqueousfusion-that is, when the crystals are heated to a certain tempera-1 turethey melt in their own water of crystallization. The latent heat offusion of such high, and consequently after pera'ture a long time andgive off a great amount of crystallized.

Its centigrade,'it will remain at that temperature for three or fourhours while cooling if em Sodium acetate is such a coinwith indifferentbodiesas, for example, glyc-' better results.

composition of two or more of certain crystalline'salts a great increasein utility and effectiveness is produced, a higher temperature can bereached, the heat may be retained for much longer period smalleraniountsof material are required, and other advantages will'result, If areceptacle be provided with such a composition and heated until all theingredients are melted, a source of heatis obtained which will remain atgradually-lowering temperature until all of the ingredients arerecrystallized. Reference is' to be had to the accompanying drawings,forming a part of this specification, in which similar characters ofreference indicate corresponding parts in all the figures.

Figure 1 is a side elevation, partly in section, of a receptacleconstructed for use with my invention. Fig. 2 is a perspective view of acarriage-warmer, showing another way Application flied October 3, 1904.Serial No. 226,998;

heat before they are entirely re- J temperature of fusion being 5&

. pouring the s, at the same time much of using my invention; and Fig. 3is a perspective view of a massage implement with myinvention appliedthereto.

1n Fig. 1, a represents a receptacle in the form of a coffee-pot; but itwillbe obvious that the same principle could be applied to any otherreceptacle-such, for example, as a teapot, a dinner-pail, a soupoi, meatdish, a milk-bottle, a hot-water bag, a glue-pot, a chest for holdingbottles, &c. The receptacle is provided with an lnner'lining 0', eitherat the bottom or sides, or both, so as tofurnish an inner receptacle fora compound 6. Of course it will depend upon circumstances whether theinner receptacle extends entirely around the receptacle or is locatedonly at orfnear the bottom. When the receptacle is manufactured, theinner receptacle is provided with the compound and then sealedup. i p

in use the receptacle is. preferably immersed in warm or boiling wateruntil the crystals melt and then is set aside. ,It will be found to keepwarm for many hours. It-

may be heated in any other way, as by puttin'gjt on the stove; but thiswould require too much attention and care for ordinary use. In cases'inwhich the liquid to becontained in the receptacle can be-heated to aconsiderably higher temperature than that at which it is desired toretain it the necessary heat may be imparted to the composition bymerely ceptacle. .lt'will be obvious that in designing receptacles fordifierent materials the proportions and ingredients of the composition,as well as the location of the'inner receptacle, may be varied so as toretain the material at the desired temperature.

In Fig. 2, 0 represents a carriage-warmer. It may be provided with areceptacle, as before, for the composition 6, but ispreferably madehollow, so that it can be filled with the composition. It can bemade inany size and shape, and obviously the same principle can' be applied tofoot-warmers, ear-bags, stemach-bags, and an infinite variety ofarticles used for keeping different "parts of the body warm. A ma sageimplement (i may also be constructed on the same principle. It will besuperheated liquidinto the re- 2 I i l understood that all ofthese'articles may be material.

drop to that of the atmosphere.

made of metal, rubber, or any other suitable The composition to beemployed may be considerably varied; but I prefer a mixture of leadacetate and sodium sulfate. The lead-acetate crystals form (or melt) at75 centigrade and those of sodium sulfate at 33. Both have the propertyof aqueous fusion and have high latent heat of fusion. Upon heating thismixture to a point above 75 the crystals of both substances melt, and

upon cooling again to 75 the lead acetate commences to crystallize. Thisis accompanied by the liberation ofconsiderable quantities of heat, andas itproceeds slowly the entire mixture will be reheated and retained at7 5 for a long period. When the crystallization of this salt iscompleted, the resulting mass of crystals and liquid will cool to 33when the sodium sulfate will begin to crystallize. A saturated solutionof this material will cool considerably below 33 without crystallizingunless in the presence of crystals of other substances; but in this casecrystals of lead acetate are present, and consequently crystallizationwill commence immediately. The great amountof heat given out will keepthe entire mass at about 33 until the sodium sulfate is entirelycrystallized; It will thus be seen that with this composition thetemperature will remain at 75 for a long time, then drop to 33 andafterremaining stationary at that point for a considerable period willgradually In order to have a connecting-link between thetemperatures of75 and 33 and to further increase the time of cooling, a little sodiumacetate may be added. This will cause the mass to remain at 58 for atime and retard the cooling operation. An inert material, like gelatin,sand, or pulverized stone, can also be added to aid in holding the heat.

A. composition of twenty-five percent. lead acetate, fifty per cent.sodium sulfate, and twenty-five per cent. sodium acetate will act withsuch efficiency that one pound of it will evolve heat for about fifteenhours and a pound and a half fortwenty hours. It is only necessary tokeep the receptacle containing the mixture in hot water for a fewminutes in order to prepare it for this action. Another advantage ofamixture of these two or three substances lies in the fact that if thereceptacle is not heated enough to melt all of the ingredients it willstill be eflective if any one or more of thembe melted. Furthermore, ifit is not desired to heat the receptacle as high as 75 it can beretained at 58 or 33 as desired. It will be readily understood thatthereare other substances which could be employed "in the same waywithout departing from the spirit of my invention and that the latter isnot limited to those mentioned above. It will also be seen thatnon-crystalline sub stances can be added.

Having thus described my invention, Iclaim as new and desire to secureby Letters Patent 1. A composition of matter for retaining and graduallyemitting heat, comprising lead acetate and sodium sulfate.

2. A composition of matter, comprising lead acetate, sodium sulfate, andsodium ace tate.

3. A composition of matter containing about twenty-five per cent. oflead acetate, fifty per cent. of sodium sulfate, and twenty-five percent. of sodium acetate.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

v EMIL KAFKA. Witnesses: CARL FLEISHMAN, JNo. M. BITTER.

